Pentax
K-3 Mark III
APS-C DSLR flagship with optical viewfinder and weather sealing.
$1,999
Released Apr 2021
Sigma
fp L
World's smallest full-frame interchangeable camera with 61MP and L-mount.
$2,499
Released Jul 2021
fp L is 2 months newer.
Wins
K-3 Mark III
Wins
fp L
8 categories tied
Check current prices
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TL;DR — Key differences
- Bfp L has higher Resolution (61 MP vs 25.7 MP)
- AK-3 Mark III has higher AF points / zones (101 vs 49)
- AK-3 Mark III has higher RAW buffer depth (120 frames vs 60 frames)
- AK-3 Mark III has higher EVF resolution (3,690,000 vs 2,360,000)
- AK-3 Mark III has lower Weight (520 g vs 720 g)
Key specs at a glance
Size and weight, to scale
K-3 Mark III
138 × 98 × 88 mm
520 g (1.15 lb / 18.34 oz)
fp L
138 × 98 × 88 mm
720 g (1.59 lb / 25.40 oz)
K-3 Mark III and fp L share virtually identical body dimensions.
K-3 Mark III is 200 g lighter than fp L.
Depth (front-to-back): 88mm K-3 Mark III · 88mm fp L
Sensor size, to scale
K-3 Mark III
23.5 × 15.6 mm · APS-C
367 mm² area
fp L
36 × 24 mm · Full Frame
864 mm² area
2.4× larger sensor area = shallower depth of field and better low-light performance.
Lens ecosystem
Native lens selection
K-3 Mark III
✓ more lensesPentax K
70+
native lenses available
fp L: mount data unavailable
Counts include current first-party and major third-party native autofocus lenses.
Use-case scoring
Which one for what?
Algorithmic scores from verified specs · 10 = best in class
Why pick one over the other
Reasons to choose
K-3 Mark III
AF points / zones
101 vs 49 — higher is better
RAW buffer depth
120 frames vs 60 frames — higher is better
EVF resolution
3,690,000 vs 2,360,000 — higher is better
Weight
520 g vs 720 g — lower is better
Burst (mechanical)
8 fps vs 6 fps — higher is better
Burst (electronic)
20 fps vs 15 fps — higher is better
IBIS effectiveness
7 stops vs 6 stops — higher is better
AF frame coverage
100 % vs 90 % — higher is better
Reasons to choose
fp L
AF low-light limit
-5 EV vs -3 EV — lower is better
Resolution
61 MP vs 25.7 MP — higher is better
AA filter
Only fp L supports it
Both cameras share
- ✓ISO min (native) — Both 100
- ✓ISO max (native) — Both 25,600
- ✓Eye AF — Both support eye af
- ✓Animal / bird AF — Both support animal / bird af
- ✓Pre-Capture / Pre-Release — Both support pre-capture / pre-release
- ✓4K max frame rate — Both 60 fps
Pros & cons at a glance
Editorially curated highlights and trade-offs.
K-3 Mark III
Pros
- ✓Optical viewfinder
- ✓Weather sealed
- ✓IBIS in DSLR
Cons
- –DSLR system declining
- –APS-C
- –Limited video
fp L
Pros
- ✓Tiny full-frame
- ✓61MP
- ✓L-mount
- ✓Unique industrial design
Cons
- –No IBIS
- –Small battery
- –Minimal ergonomics
Full specifications
✓ = category winner
Frequently asked
Quick answers generated from verified specs.
Which is better for landscape, K-3 Mark III or fp L?
fp L scores 9.0/10 versus 5.0/10 for K-3 Mark III — 61MP — massive detail for large prints.
What's the resolution difference between the K-3 Mark III and fp L?
K-3 Mark III is 25.7 MP and fp L is 61 MP, so the fp L captures more detail for cropping and large prints.
Do the K-3 Mark III and fp L have in-body image stabilization?
K-3 Mark III has 7-stop in-body image stabilization, while fp L has 6-stop in-body image stabilization.
Which shoots faster bursts — the K-3 Mark III or the fp L?
K-3 Mark III reaches 20 fps electronic. fp L reaches 15 fps electronic.
What's the weight difference between the K-3 Mark III and fp L?
K-3 Mark III weighs 520 g and fp L weighs 720 g, so the K-3 Mark III is 200 g lighter.
Do the K-3 Mark III and fp L record 4K video?
K-3 Mark III: 4K up to 60p. fp L: 4K up to 60p.
Are the K-3 Mark III and fp L weather sealed?
K-3 Mark III: Yes. fp L: Yes.
Which has better battery life?
Rated battery life is 640 shots (CIPA) for the K-3 Mark III and 640 shots for the fp L, giving the fp L the edge.
How much does each cost?
K-3 Mark III launched at $1,999 and fp L at $2,499. The K-3 Mark III is $500 less.
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed May 2026.